function s1_goto_dir(){
 cd "$1"
}

function s2_touch_empty_file_with_given_name(){
 touch "$1"
}

function s3_make_directories(){
 mkdir -p projects/{git,backup}
}

function s4_create_6_files(){
 touch projects/linux{1,2}_{centos,redhat,c_programming}
}
function s5_make_directories_in_git(){
 mkdir -p projects/git/linux{1,2}
}

function s6_move_files_to_dir_1_or_2(){
 mv ./projects/linux1_* projects/git/linux1 && mv ./projects/linux2_* projects/git/linux2
}

function s7_create_package_and_compress(){
 tar -czvf ./projects/backup/git.tar.gz projects/git
}

function s8_delete_dir_git(){
 rm -rf ./projects/git
}

function s9_recover_from_git_tar_gz_backup(){
 tar -zxvf ./projects/backup/git.tar.gz ./ projects/
}

function s10_create_package_and_compress(){
 tar -jcvf ./projects/backup/git.tar.bz2 ./projects/git
}

function s11_find_and_sort_alphabetically_all_created_files_and_dirs(){
 find ./projects |sort
}

function s12_get_next_15_minutes_boundaey(){
 date -d"@$(($(date +%s) -$(date +%s)%900 +900))" +"%Y-%m-%d_%H:%M:%S"
}
